I want to use a 555 to trigger a 1 second rotation of a DC motor. I can get one LM555 timer to function properly but have half a dozen timers that will trigger and run only as long as the neg voltage is present but not allow the duration to run after the trigger is applied. Several of the 555's are new. Is there something I'm missiing in the standard one shot circuit or do I need to try multiple timers until I find ones that will actually work as advertised? Do I need to set up a voltage divider to create a ground rather than +/- voltage to make it work?

 

Feedback and Suggestions Forum for providing feedback and suggestions about All About Circuits, including corrections to the e-book. This forum is not for getting help with technical questions.

This was neither feedback nor a suggestion, so I have moved it to a more appropriate forum.

 

555 timers have a good reputation ie, they usually work.
If you posted a drawing of what you've made, we might be able to see what can be improved.